diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 186bc19..611d0c4 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -1051,6 +1051,8 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 	ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
 	dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
 
+	ubi_update_fastmap(ubi);
+
 	/*
 	 * Before freeing anything, we have to stop the background thread to
 	 * prevent it from doing anything on this device while we are freeing.
@@ -1058,10 +1060,6 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway)
 	if (ubi->bgt_thread)
 		kthread_stop(ubi->bgt_thread);
 
-	/* If no fastmap is present on the FLASH write one. */
-	if (!ubi->fm)
-		ubi_update_fastmap(ubi);
-
 	/*
 	 * Get a reference to the device in order to prevent 'dev_release()'
 	 * from freeing the @ubi object.